Updates to data maintained by a distributed database management system (“DBMS”) may be subject to a delay between the time the request to update data is received and the time the update has been fully processed. A distributed DBMS may comprise a collection of items that can be both distributed and replicated across a number of computing nodes. On each computing node, a subset of the item collection as well as various index structures may be maintained on one or more storage devices. Processing an update may involve communication between the computing nodes as well as various high-latency write operations on the storage devices. These factors may contribute to the delay in processing an update.
The delay in processing updates may contribute to data consistency issues. One such issue involves clients being unable to read their own updates. A client may submit a request to change an item of data to a distributed DBMS. Immediately or soon thereafter, the client may issue a request to read the same item. Depending upon the amount of delay, the computing node processing the request and the time the computing node receives the read request, the results may be consistent or inconsistent with the client's most recent update.